Because domestic publicity of anti-smoking and the people's awareness of health are enhanced, electronic cigarettes, which serve as the substitute of traditional tobacco, have been more and more widely used. An existing electronic cigarette comprises a battery assembly and an atomizer assembly connected to the battery assembly. The battery assembly is provided with a battery. The atomizer assembly is provided with a heating wire, an ultrasonic atomizer or the like. The atomizer assembly and the battery are electrically connected to each other. The atomizer assembly is provided with an external thread, and the battery assembly is provided with an internal thread. Therefore, the atomizer assembly and the battery assembly are connected to each other in thread connection. However, with such connection manner, the atomizer assembly and the battery assembly may be offset with respect to each other. The connection between the atomizer assembly and the battery assembly in such manner may be relaxed easily with poor reliability and bad users' feel.